1. Field of the Invention
This invention relates to a recording and reproducing apparatus for recording and reproducing video signals generally, and more particularly to an improvement of a video signal erasing means for erasing the recorded video signals on a track formed beforehand in a magnetic disc.
2. Description of the Related Art
In this type of apparatus, the erasing processing to erase the recorded video signals on a track on a magnetic disc has been accomplished by overlapping a new erasing signal on the video signals to be erased on the track.
In this conventional apparatus, however, in the case when the track position accessed by reproducing head deviates from the absolute track position recorded, the signal portion on the deviated part of the track is not erased in execution of erasing, resulting in mis-erasure.
To compensate the track deviation, it has been considered that before execution of erasing, the head position is moved by an estimated deviation of the track position recorded from that accessed by the reproducing head. However, it is usually difficult to estimate the amount of track deviation. If this procedure is practiced, there is a disadvantage in that no complete erasure is obtained if a plurality of erasing operations is not executed on the same track, and in that such an erasing procedure would take much time.
Another disadvantage of the conventional apparatus is that when executing the erasure of a plurality of continuous tracks from the track position being accessed currently, the reproduced video signals on the first track can surely be monitored by the operator while the video signals on the subsequent tracks to be erased can not be monitored, resulting in mis-erasure, if continuous erasure is executed.